tailieunhanh - Planar Geometry of 4-Substituted-2,2'-bipyridines Synthesized by Sonogashira and Suzuki Cross-Coupling Reactions

In this paper, we report the synthesis, geometry and molecular arrangement in the crystals of two compounds, namely 4-(ferrocenylethynyl)-2,2'-bipyridine (I) and 4-ferrocenyl-2,2'-bipyridine (II) which were synthesized by the palladium catalyzed Sonogashira and Suzuki-Miyaura cross-coupling reactions. | ISSN 1063-7745 Crystallography Reports 2015 Vol. 60 No. 7 pp. 1100 1105. Pleiades Publishing Inc. 2015. STRUCTURE OF ORGANIC COMPOUNDS Planar Geometry of 4-Substituted-2 2 -bipyridines Synthesized by Sonogashira and Suzuki Cross-Coupling Reactions1 T. T. Luong Thia N. Nguyen Bicha H. Nguyena and L. Van Meerveltb a ChemistryDepartment Hanoi National University of Education A4 136 Xuan Thuy Cau Giay Vietnam b Chemistry Department KU Leuven Celestijnenlaan 200F B-3001 Heverlee Belgium e-mail thuyltt@ Received February 18 2014 Abstract Two 4-substituted 2 2 -bipyridines namely 4- ferrocenylethynyl -2 2 -bipyridine I and 4-ferro- cenyl-2 2 -bipyridine II have been synthesized and fully characterized via single-crystal X-ray diffraction and 1H and 13C NMR analyses. The π-conjugated system designed from 2 2 -bipyridine modified with the ferrocenylethynyl and ferrocenyl groups shows the desired planarity. In the crystal packing of I and II the molecules arrange themselves in head-to-tail and head-to-head motifs respectively resulting in consecutive layers of ferrocene and pyridine moieties. DOI S1063774515070160 INTRODUCTION N The 2 2 -bipyridine is one of the most widely used Fe chelate systems in coordination supramolecular and macromolecular chemistry 1 . Due to their unique N photophysical and photooptical properties 2 2 -bipyri- dine derivatives are used in the synthesis of photo- I sensitizers for dye sensitized solar cells DSSC 2 3 . The introduction of different functionalities on the N 2 2 -bipyridine moiety is based on the fact that larger Fe delocalization of the π-electrons from the aromatic N part of the molecule normally leads to higher extinction coefficients of the metal-to-ligand charge- II transfer MLCT transitions in their copper I com- plexes 4 . EXPERIMENTAL In this paper we report the synthesis geometry and Synthesis and crystallization. The synthesis of the molecular arrangement in the crystals of